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Create Colour Wise Multiple Lines Of Particles

I am creating particle animation using Canvas & JavaScript. Currently, particles are generating from an emitter randomly & falling in a direction (top right corner to bottom left corner). collision detection effect is also working on mouse hover.
problem is:
I want to create separate color-wise multiple lines of particles (e.g:- blue colored particles should be in separate a line & red in a separate line).
how could I achieve this?
Sorry for bad drawing, any reference will be very useful. Thank you in advance.
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
window.requestAnimationFrame = requestAnimationFrame;
})();
var particleArr = [],
canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
flakeCount = 700,
mouseX = -100,
mouseY = -100,
xMultiplier = 0.015
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
var rate = 0.07788656582264941;
function getRandomColor() {
// Random Color Generate
const colorArr = ["rgba(215,88,69, 1)", "rgba(117, 161, 199, 1)"]; // Blue & Orange Color
const randomColor = colorArr[Math.floor(Math.random() * colorArr.length)];
return randomColor;
}
function flow() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < flakeCount; i++) {
var flake = particleArr[i],
x = mouseX,
y = mouseY,
minDist = 150,
x2 = flake.x,
y2 = flake.y;
var dist = Math.sqrt((x2 - x) * (x2 - x) + (y2 - y) * (y2 - y)),
dx = x2 - x,
dy = y2 - y;
if (dist < minDist) {
var force = minDist / (dist * dist),
xcomp = (x - x2) / dist,
ycomp = (y - y2) / dist,
deltaV = force / 2;
// deltaV = 0.03960597468566516
flake.velX -= deltaV * xcomp;
flake.velY -= deltaV * ycomp;
// flake.velX -= deltaV * xcomp + rate;
// flake.velY -= deltaV * ycomp + rate;
} else {
flake.velX *= .98;
if (flake.velY <= flake.speed) {
flake.velY = flake.speed
}
flake.velX += Math.cos(flake.step += .05) * flake.stepSize;
}
flake.y += flake.velY;
flake.x += flake.velX;
if (flake.y >= canvas.height || flake.y <= 0) {
reset(flake);
}
if (flake.x >= canvas.width || flake.x <= 0) {
reset(flake);
}
ctx.fillStyle = particleArr[i].color;
ctx.beginPath();
ctx.arc(flake.x, flake.y, flake.size, 0, Math.PI * 2);
ctx.fill();
}
requestAnimationFrame(flow);
// setTimeout(() => {
// requestAnimationFrame(flow);
// }, 1000 / 40);
};
function reset(flake) {
let temp = (Math.random() * 1) + 0.5;
flake.x = canvas.width;
flake.y = 50;
// flake.size = (Math.random() * 3) + 5;
flake.size = 6.692053245649504;
flake.speed = (Math.random() * 7) + 0.5;
flake.velY = flake.speed;
flake.velX = -xMultiplier * canvas.width * temp;
// flake.opacity = (Math.random() * 0.5) + 0.3;
}
function init() {
for (var i = 0; i < flakeCount; i++) {
var x = canvas.width,
y = 50,
size = 6.692053245649504,
speed = 0;
// size = (Math.random() * 3) + 5, // can change 3 to 4
// speed = (Math.random() * 1) + 0.5;
// opacity = (Math.random() * 0.5) + 0.3;
particleArr.push({
speed: speed,
velY: speed,
velX: -xMultiplier * canvas.width * speed,
x: x,
y: y,
size: size,
stepSize: (Math.random()) / 30,
step: 0,
angle: 360,
color: getRandomColor()
// opacity: opacity
});
}
requestAnimationFrame(flow);
// flow();
};
canvas.addEventListener("mousemove", function(e) {
mouseX = e.clientX,
mouseY = e.clientY
});
window.addEventListener( 'resize', onWindowResize, false );
function onWindowResize() {
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
}
init();
canvas{
background-color: #000000 !important;
}
body {
margin: 0;
overflow: hidden;
}`
<canvas id="canvas"></canvas>

Javascript Animation(Canvas) not working in firefox, Edge but works on Chrome

This is a code from codepen. I am trying to work on this one. This code works on chrome but does not work in firefox or edge. I tried to solve the issue but could not fix it. Is the problem with requestAnimationFrame or something else? Can anyone please help? Here is the codepen link: https://codepen.io/iremlopsum/pen/MKNaxd
var canvas = document.querySelector("#scene"),
ctx = canvas.getContext("2d"),
particles = [],
amount = 0,
mouse = {
x: 0,
y: 0
},
radius = 0.7; //Init radius of the force field
var colors = ["rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)"];
var colorsTwo = ["rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)", "rgba(255,255,255, .6)"];
var copy = "Mighty Byte"; // Text to display
var initSize = Math.floor(Math.random() * .6) + 1 ;
var hoverSize = initSize + .7;
var ww = canvas.width = window.innerWidth;
var wh = canvas.height = window.innerHeight;
function Particle(x, y) {
this.x = Math.random() * ww;
this.y = Math.random() * wh;
this.dest = {
x: x,
y: y
};
//this.r = Math.random() * 1; // the size of bubbles
this.vx = (Math.random() - 0.5) * 2;
this.vy = (Math.random() - 0.5) * 2;
this.accX = 0;
this.accY = 0;
this.friction = Math.random() * 0.015 + 0.94; // force of bounce, just try to change 0.015 to 0.5
//this.color = colors[Math.floor(Math.random() * 10)];
//this.colorTwo = colorsTwo[Math.floor(Math.random() * 10)];
}
Particle.prototype.render = function() {
this.accX = (this.dest.x - this.x) / 200; //acceleration for X
this.accY = (this.dest.y - this.y) / 200; //acceleration for Y
this.vx += this.accX;
this.vy += this.accY;
this.vx *= this.friction;
this.vy *= this.friction;
this.x += this.vx;
this.y += this.vy;
ctx.fillStyle = this.color;
ctx.beginPath();
ctx.arc(this.x, this.y, this.r, Math.PI * 2, false);
ctx.fill();
var a = this.x - mouse.x;
var b = this.y - mouse.y;
var distance = Math.sqrt(a * a + b * b);
if (distance < (radius * 70)) {
this.accX = (this.x - mouse.x) / 20; //acceleration on mouseover X, smaller faster
this.accY = (this.y - mouse.y) / 20; //acceleration on mouseover Y, smaller faster
this.vx += this.accX;
this.vy += this.accY;
//ctx.fillStyle = this.colorTwo;
}
if (distance < (radius * 70)) {
this.colorTwo = colorsTwo[Math.floor(Math.random() * 10)];
ctx.fillStyle = this.colorTwo;
this.r = hoverSize; // the size of bubbles
}
if (distance > (radius * 70)) {
this.colorOne = colors[Math.floor(Math.random() * 10)];
ctx.fillStyle = this.colorOne;
this.r = initSize
}
}
function onMouseMove(e) {
mouse.x = e.clientX;
mouse.y = e.clientY;
}
function initScene() {
ww = canvas.width = window.innerWidth;
wh = canvas.height = window.innerHeight;
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.font = "bold " + (ww / 10) + "px sans-serif"; // Size of the text
ctx.textAlign = "center";
ctx.fillText(copy, ww / 2, wh / 2); //Centering
var data = ctx.getImageData(0, 0, ww, wh).data;
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.globalCompositeOperation = "screen";
particles = [];
for (var i = 0; i < ww; i += Math.round(ww / 400)) { //400 here represents the amount of particles
for (var j = 0; j < wh; j += Math.round(ww / 400)) {
if (data[((i + j * ww) * 4) + 3] > 250) {
particles.push(new Particle(i, j));
}
}
}
amount = particles.length;
}
function onMouseClick() {
radius = 4; //onclick expand radius
}
function offMouseClick() {
radius = 0.5; //offClick init radius
}
function delayedInitRadius() {
setTimeout(offMouseClick, 500); //delay for offClick init radius
}
function render(a) {
requestAnimationFrame(render);
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < amount; i++) {
particles[i].render();
}
};
window.addEventListener("resize", initScene);
window.addEventListener("mousemove", onMouseMove);
window.addEventListener("mousedown", onMouseClick);
window.addEventListener("mouseup", delayedInitRadius);
initScene();
requestAnimationFrame(render);

Why circles are vibrating on collision (Canvas)

I have been creating a clone of agar.io and I don't understand why the circles start vibrating when they touch each other. Below is my code:
var
canvas,
ctx,
width = innerWidth,
height = innerHeight,
mouseX = 0,
mouseY = 0;
var
camera = {
x: 0,
y: 0,
update: function(obj) {
this.x = obj.x - width / 2;
this.y = obj.y - height / 2;
}
},
player = {
defaultMass: 54,
x: 0,
y: 0,
blobs: [],
update: function() {
for (var i = 0; i < this.blobs.length; i++) {
var x = mouseX + camera.x - this.blobs[i].x;
var y = mouseY + camera.y - this.blobs[i].y;
var length = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
var speed = 54 / this.blobs[i].mass;
this.blobs[i].velX = x / length * speed * Math.min(1, Math.pow(x / this.blobs[i].mass, 2));
this.blobs[i].velY = y / length * speed * Math.min(1, Math.pow(x / this.blobs[i].mass, 2));
this.blobs[i].x += this.blobs[i].velX;
this.blobs[i].y += this.blobs[i].velY;
for (var j = 0; j < this.blobs.length; j++) {
if (j != i && this.blobs[i] !== undefined) {
var blob1 = this.blobs[i];
var blob2 = this.blobs[j];
var dist = Math.sqrt(Math.pow(blob2.x - blob1.x, 2) + Math.pow(blob2.y - blob1.y, 2));
if (dist < blob1.mass + blob2.mass) {
if (this.blobs[i].x < this.blobs[j].x) {
this.blobs[i].x--;
} else if (this.blobs[i].x > this.blobs[j].x) {
this.blobs[i].x++;
}
if (this.blobs[i].y < this.blobs[j].y) {
this.blobs[i].y--;
} else if ((this.blobs[i].y > this.blobs[j].y)) {
this.blobs[i].y++;
}
}
}
}
}
this.x += (mouseX - width / 2) / (width / 2) * 1;
this.y += (mouseY - height / 2) / (height / 2) * 1
},
split: function(cell) {
cell.mass /= 2;
this.blobs.push({
x: cell.x,
y: cell.y,
mass: cell.mass
});
},
draw: function() {
for (var i = 0; i < this.blobs.length; i++) {
ctx.fillStyle = "red";
ctx.beginPath();
ctx.arc(-camera.x + this.blobs[i].x, -camera.y + this.blobs[i].y, this.blobs[i].mass, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
}
}
};
function handleMouseMove(e) {
mouseX = e.clientX;
mouseY = e.clientY;
}
function setup() {
canvas = document.getElementById("game");
ctx = canvas.getContext("2d");
canvas.width = width;
canvas.height = height;
addEventListener("mousemove", handleMouseMove);
player.blobs.push({
x: 0,
y: 0,
mass: player.defaultMass
});
player.blobs.push({
x: 100,
y: 100,
mass: player.defaultMass / 2
});
player.blobs.push({
x: 100,
y: 100,
mass: player.defaultMass * 2
});
var loop = function() {
update();
draw();
requestAnimationFrame(loop);
}
requestAnimationFrame(loop);
}
function update() {
camera.update(player.blobs[0]);
player.update();
}
function draw() {
ctx.fillStyle = "#fff";
ctx.fillRect(0, 0, width, height);
player.draw();
}
setup();
body {
margin: 0;
padding: 0;
}
<canvas id="game">kindly update your browser.</canvas>

Separating circles
Your separation code was not correct. Use the vector between them to get the new pos.
The vector between them
To find if two circles are intercepting find the length of the vector from one to the next
The two circles.
var cir1 = {x : 100, y : 100, r : 120}; // r is the radius
var cir2 = {x : 250, y : 280, r : 150}; // r is the radius
The vector from cir2 to cir1
var vx = cir2.x - cir1.x;
var vy = cir2.y - cir1.y;
The length of the vector
var len = Math.sqrt(x * x + y * y);
// or use the ES6 Math.hypot function
/* var len = Math.hypot(x,y); */
The circles overlap if the sum of the radii is greater than the length of the vector between them
if(cir1.r + cir2.r > len){ // circles overlap
Normalise the vector
If they overlap you need to move one away from the other. There are many ways to do this, the simplest way is to move one circle along the line between them.
First normalise the vector from cir1 to cir2 by dividing by its (vector) length.
vx \= len;
vy \= len;
Note that the length could be zero. If this happens then you will get NaN in further calculations. If you suspect you may get one circle at the same location as another the easiest way to deal with the zero move one circle a little.
// replace the two lines above with
if(len === 0){ // circles are on top of each other
vx = 1; // move the circle (abstracted into the vector)
}else{
vx \= len; // normalise the vector
vy \= len;
}
Move circle/s to just touch
Now you have the normalised vector which is 1 unit long you can make it any length you need by multiplying the two scalars vx, vy with the desired length which in this case is the sum of the two circles radii.
var mx = vx * (cir1.r + cir2.r); // move distance
var my = vy * (cir1.r + cir2.r);
.Only use one of the following methods.
You can now position one of the circles the correct distance so that they just touch
// move cir1
cir1.x = cir2.x - mx;
cir1.y = cir2.y - my;
Or move the second circle
cir2.x = cir1.x + mx;
cir2.y = cir1.y + my;
Or move both circles but you will have to first find the proportional center between the two
var pLen = cir1.r / (cir1.r + cir2.r); // find the ratio of the radii
var cx = cir1.x + pLen * vx * len; // find the proportional center between
var cy = cir1.y + pLen * vy * len; // the two circles
Then move both circles away from that point by their radii
cir1.x = cx - vx * cir1.r; // move circle 1 away from the shared center
cir1.y = cy - vy * cir1.r;
cir2.x = cx + vx * cir2.r; // move circle 2 away from the shared center
cir2.y = cy + vy * cir2.r;
DEMO
Copy of OP's snippet with mods to fix problem by moving the the first circle blob1 away from the second blob2 and assuming they will never be at the same spot (no divide by zero)
var
canvas,
ctx,
width = innerWidth,
height = innerHeight,
mouseX = 0,
mouseY = 0;
var
camera = {
x: 0,
y: 0,
update: function(obj) {
this.x = obj.x - width / 2;
this.y = obj.y - height / 2;
}
},
player = {
defaultMass: 54,
x: 0,
y: 0,
blobs: [],
update: function() {
for (var i = 0; i < this.blobs.length; i++) {
var x = mouseX + camera.x - this.blobs[i].x;
var y = mouseY + camera.y - this.blobs[i].y;
var length = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
var speed = 54 / this.blobs[i].mass;
this.blobs[i].velX = x / length * speed * Math.min(1, Math.pow(x / this.blobs[i].mass, 2));
this.blobs[i].velY = y / length * speed * Math.min(1, Math.pow(x / this.blobs[i].mass, 2));
this.blobs[i].x += this.blobs[i].velX;
this.blobs[i].y += this.blobs[i].velY;
for (var j = 0; j < this.blobs.length; j++) {
if (j != i && this.blobs[i] !== undefined) {
var blob1 = this.blobs[i];
var blob2 = this.blobs[j];
var x = blob2.x - blob1.x; // get the vector from blob1 to blob2
var y = blob2.y - blob1.y; //
var dist = Math.sqrt(x * x + y * y); // get the distance between the two blobs
if (dist < blob1.mass + blob2.mass) { // if the distance is less than the 2 radius
// if there is overlap move blob one along the line between the two the distance of the two radius
x /= dist; // normalize the vector. This makes the vector 1 unit long
y /= dist;
// multiplying the normalised vector by the correct distance between the two
// and subtracting that distance from the blob 2 give the new pos of
// blob 1
blob1.x = blob2.x - x * (blob1.mass + blob2.mass);
blob1.y = blob2.y - y * (blob1.mass + blob2.mass);
}
}
}
}
this.x += (mouseX - width / 2) / (width / 2) * 1;
this.y += (mouseY - height / 2) / (height / 2) * 1
},
split: function(cell) {
cell.mass /= 2;
this.blobs.push({
x: cell.x,
y: cell.y,
mass: cell.mass
});
},
draw: function() {
for (var i = 0; i < this.blobs.length; i++) {
ctx.fillStyle = "red";
ctx.beginPath();
ctx.arc(-camera.x + this.blobs[i].x, -camera.y + this.blobs[i].y, this.blobs[i].mass, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
}
}
};
function handleMouseMove(e) {
mouseX = e.clientX;
mouseY = e.clientY;
}
function setup() {
canvas = document.getElementById("game");
ctx = canvas.getContext("2d");
canvas.width = width;
canvas.height = height;
addEventListener("mousemove", handleMouseMove);
player.blobs.push({
x: 0,
y: 0,
mass: player.defaultMass
});
player.blobs.push({
x: 100,
y: 100,
mass: player.defaultMass / 2
});
player.blobs.push({
x: 100,
y: 100,
mass: player.defaultMass * 2
});
var loop = function() {
update();
draw();
requestAnimationFrame(loop);
}
requestAnimationFrame(loop);
}
function update() {
camera.update(player.blobs[0]);
player.update();
}
function draw() {
ctx.fillStyle = "#fff";
ctx.fillRect(0, 0, width, height);
player.draw();
}
setup();
body {
margin: 0;
padding: 0;
}
<canvas id="game">kindly update your browser.</canvas>

var
canvas,
ctx,
width = innerWidth,
height = innerHeight,
mouseX = 0,
mouseY = 0;
var
camera = {
x: 0,
y: 0,
update: function(obj) {
this.x = obj.x - width / 2;
this.y = obj.y - height / 2;
}
},
player = {
defaultMass: 54,
x: 0,
y: 0,
blobs: [],
update: function() {
for (var i = 0; i < this.blobs.length; i++) {
var x = mouseX + camera.x - this.blobs[i].x;
var y = mouseY + camera.y - this.blobs[i].y;
var length = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
var speed = 54 / this.blobs[i].mass;
this.blobs[i].velX = x / length * speed * Math.min(1, Math.pow(x / this.blobs[i].mass, 2));
this.blobs[i].velY = y / length * speed * Math.min(1, Math.pow(x / this.blobs[i].mass, 2));
this.blobs[i].x += this.blobs[i].velX;
this.blobs[i].y += this.blobs[i].velY;
for (var j = 0; j < this.blobs.length; j++) {
if (j != i && this.blobs[i] !== undefined) {
var blob1 = this.blobs[i];
var blob2 = this.blobs[j];
var dist = Math.sqrt(Math.pow(blob2.x - blob1.x, 2) + Math.pow(blob2.y - blob1.y, 2));
if (dist < blob1.mass + blob2.mass) {
if (this.blobs[i].x < this.blobs[j].x) {
this.blobs[i].x--;
} else if (this.blobs[i].x > this.blobs[j].x) {
this.blobs[i].x++;
}
if (this.blobs[i].y < this.blobs[j].y) {
this.blobs[i].y--;
} else if ((this.blobs[i].y > this.blobs[j].y)) {
this.blobs[i].y++;
}
}
}
}
}
this.x += (mouseX - width / 2) / (width / 2) * 1;
this.y += (mouseY - height / 2) / (height / 2) * 1
},
split: function(cell) {
cell.mass /= 2;
this.blobs.push({
x: cell.x,
y: cell.y,
mass: cell.mass
});
},
draw: function() {
for (var i = 0; i < this.blobs.length; i++) {
ctx.fillStyle = "red";
ctx.beginPath();
ctx.arc(-camera.x + this.blobs[i].x, -camera.y + this.blobs[i].y, this.blobs[i].mass, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
}
}
};
function handleMouseMove(e) {
mouseX = e.clientX;
mouseY = e.clientY;
}
function setup() {
canvas = document.getElementById("game");
ctx = canvas.getContext("2d");
canvas.width = width;
canvas.height = height;
addEventListener("mousemove", handleMouseMove);
player.blobs.push({
x: 0,
y: 0,
mass: player.defaultMass
});
player.blobs.push({
x: 100,
y: 100,
mass: player.defaultMass / 2
});
player.blobs.push({
x: 100,
y: 100,
mass: player.defaultMass * 2
});
var loop = function() {
update();
draw();
requestAnimationFrame(loop);
}
requestAnimationFrame(loop);
}
function update() {
camera.update(player.blobs[0]);
player.update();
}
function draw() {
ctx.fillStyle = "#fff";
ctx.fillRect(0, 0, width, height);
player.draw();
}
setup();
body {
margin: 0;
padding: 0;
}
<canvas id="game">kindly update your browser.</canvas>

Canvas onClick add to array

I got this HTML5 canvas project I'm struggling with.
Basically I'm trying to add a new particle on click.
And the particles is pushed to the particles array, but
the particle does not show. I can see that the particle is pushed to the array with the mouse coordinates, but it doesn't seem like the last particle is drawn.
What am I doing wrong?
See example.
// Request animation frame
var requestAnimationFrame = window.requestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.msRequestAnimationFrame;
// Canvas
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
// Set full-screen
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
// Options
var num = 100; // Number of particles to draw
var size = 2; // Particle size
var color = '#dd64e6'; // Particle color
var min_speed = .3; // Particle min speed
var max_speed = 2; // Particle max speed
var dist = 100; // Max distance before line gets cut
var dist_sq = dist * dist; // Dist squared
var line_width = 2; // Line width
var background = '#181b23'; // Background color
var line_color = '#1d2631'; // Line color
var fps = 60;
var now, delta;
var then = Date.now();
var interval = 1000 / fps;
if (/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)) {
num = 10;
fps = 29;
}
// Particles array
var particles = [];
for (var i = 0; i < num; i++) {
particles.push(
new create_particle(false, false)
);
}
// Lets animate the particle
function draw() {
// Loop
requestAnimationFrame(draw);
now = Date.now();
delta = now - then;
if (delta > interval) {
then = now - (delta % interval);
// Background
ctx.fillStyle = background;
ctx.fillRect(0, 0, canvas.width, canvas.height);
// Lets draw particles from the array now
draw_particles();
}
}
// Draw particles
function draw_particles() {
for (var t = 0; t < num; t++) {
// This particle
var p = particles[t];
for (var q = t + 1; q < num; q++) {
// Check X first, maybe we don't need to
// calculate Y
var x = particles[q].x - p.x;
if ((x *= x) < dist_sq) {
// Check passed, calculate Y
var y = particles[q].y - p.y;
if (x + (y * y) < dist_sq) {
// Check passed, draw line
draw_line(p.x, p.y, particles[q].x, particles[q].y);
}
}
}
// Color
ctx.fillStyle = color;
// Circle path
ctx.beginPath();
ctx.arc(p.x, p.y, p.radius, Math.PI * 2, false);
ctx.fill();
// Lets use the velocity now
p.x += p.vx;
p.y += p.vy;
// If there is only 1 particle
// show X, Y, and velocity
if (num === 1) {
ctx.fillText('Y:' + p.y, 20, 20);
ctx.fillText('X:' + p.x, 20, 40);
ctx.fillText('YV:' + p.vy, 20, 60);
ctx.fillText('XV:' + p.vx, 20, 80);
}
// To prevent the balls from moving out of the canvas
if (p.x < size) p.vx *= (p.vx / -p.vx);
if (p.y < size) p.vy *= (p.vy / -p.vy);
if (p.x > canvas.width - size) p.vx *= (-p.vx / p.vx);
if (p.y > canvas.height - size) p.vy *= (-p.vy / p.vy);
}
}
// Return a particle object
function create_particle(xPos, yPos) {
// Position
if (xPos == false && yPos == false) {
this.x = Math.random() * canvas.width;
this.y = Math.random() * canvas.height;
} else {
this.x = xPos;
this.y = yPos;
}
// Velocity
this.vx = random_int_between(min_speed, max_speed);
this.vy = random_int_between(min_speed, max_speed);
// Size
this.radius = size;
console.log('particle created at: ' + this.x + ', ' + this.y);
}
// Returns an random integer, positive or negative
// between the given value
function random_int_between(min, max) {
var num = Math.floor(Math.random() * max) - min;
num *= Math.floor(Math.random() * 2) == 1 ? 1 : -1;
return num;
}
// Draw a line between 2 particles
// given the particles x and y position
function draw_line(p_x, p_y, p2_x, p2_y) {
ctx.beginPath();
ctx.lineWidth = line_width;
ctx.strokeStyle = line_color;
ctx.moveTo(p_x, p_y);
ctx.lineTo(p2_x, p2_y);
ctx.stroke();
}
// When the canvas is clicked
// add new particle
function clicked(e) {
var mouseXpos, mouseYpos;
if (e.offsetX) {
mouseXpos = e.offsetX;
mouseYpos = e.offsetY;
} else if (e.layerX) {
mouseXpos = e.layerX;
mouseYpos = e.layerY;
}
particles.push(
new create_particle(mouseXpos, mouseYpos)
);
}
canvas.addEventListener('click', function(e) {
clicked(e);
}, false);
draw();
<!DOCTYPE html>
<html>
<head>
<style>
* {margin:0;padding:0;overflow:hidden;}
</style>
</head>
<body>
<canvas id="canvas">{{-- The background --}}</canvas>
</body>
</html>

Well since no one else answered this other than in a comment, I thought I would answer it so that others might not wonder about the same thing.
The problem is that you use a variable "num" to hold the number of particles. If you instead use "particles.length" you can
// Request animation frame
var requestAnimationFrame = window.requestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.msRequestAnimationFrame;
// Canvas
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
// Set full-screen
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
// Options
var num = 100; // Number of particles to draw
var size = 2; // Particle size
var color = '#dd64e6'; // Particle color
var min_speed = .3; // Particle min speed
var max_speed = 2; // Particle max speed
var dist = 100; // Max distance before line gets cut
var dist_sq = dist * dist; // Dist squared
var line_width = 2; // Line width
var background = '#181b23'; // Background color
var line_color = '#1d2631'; // Line color
var fps = 60;
var now, delta;
var then = Date.now();
var interval = 1000 / fps;
if (/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)) {
num = 10;
fps = 29;
}
// Particles array
var particles = [];
for (var i = 0; i < num; i++) {
particles.push(
new create_particle(false, false)
);
}
// Lets animate the particle
function draw() {
// Loop
requestAnimationFrame(draw);
now = Date.now();
delta = now - then;
if (delta > interval) {
then = now - (delta % interval);
// Background
ctx.fillStyle = background;
ctx.fillRect(0, 0, canvas.width, canvas.height);
// Lets draw particles from the array now
draw_particles();
}
}
// Draw particles
function draw_particles() {
for (var t = 0; t < particles.length; t++) {
// This particle
var p = particles[t];
for (var q = t + 1; q < particles.length; q++) {
// Check X first, maybe we don't need to
// calculate Y
var x = particles[q].x - p.x;
if ((x *= x) < dist_sq) {
// Check passed, calculate Y
var y = particles[q].y - p.y;
if (x + (y * y) < dist_sq) {
// Check passed, draw line
draw_line(p.x, p.y, particles[q].x, particles[q].y);
}
}
}
// Color
ctx.fillStyle = color;
// Circle path
ctx.beginPath();
ctx.arc(p.x, p.y, p.radius, Math.PI * 2, false);
ctx.fill();
// Lets use the velocity now
p.x += p.vx;
p.y += p.vy;
// If there is only 1 particle
// show X, Y, and velocity
if (num === 1) {
ctx.fillText('Y:' + p.y, 20, 20);
ctx.fillText('X:' + p.x, 20, 40);
ctx.fillText('YV:' + p.vy, 20, 60);
ctx.fillText('XV:' + p.vx, 20, 80);
}
// To prevent the balls from moving out of the canvas
if (p.x < size) p.vx *= (p.vx / -p.vx);
if (p.y < size) p.vy *= (p.vy / -p.vy);
if (p.x > canvas.width - size) p.vx *= (-p.vx / p.vx);
if (p.y > canvas.height - size) p.vy *= (-p.vy / p.vy);
}
}
// Return a particle object
function create_particle(xPos, yPos) {
// Position
if (xPos == false && yPos == false) {
this.x = Math.random() * canvas.width;
this.y = Math.random() * canvas.height;
} else {
this.x = xPos;
this.y = yPos;
}
// Velocity
this.vx = random_int_between(min_speed, max_speed);
this.vy = random_int_between(min_speed, max_speed);
// Size
this.radius = size;
console.log('particle created at: ' + this.x + ', ' + this.y);
}
// Returns an random integer, positive or negative
// between the given value
function random_int_between(min, max) {
var num = Math.floor(Math.random() * max) - min;
num *= Math.floor(Math.random() * 2) == 1 ? 1 : -1;
return num;
}
// Draw a line between 2 particles
// given the particles x and y position
function draw_line(p_x, p_y, p2_x, p2_y) {
ctx.beginPath();
ctx.lineWidth = line_width;
ctx.strokeStyle = line_color;
ctx.moveTo(p_x, p_y);
ctx.lineTo(p2_x, p2_y);
ctx.stroke();
}
// When the canvas is clicked
// add new particle
function clicked(e) {
var mouseXpos, mouseYpos;
if (e.offsetX) {
mouseXpos = e.offsetX;
mouseYpos = e.offsetY;
} else if (e.layerX) {
mouseXpos = e.layerX;
mouseYpos = e.layerY;
}
particles.push(
new create_particle(mouseXpos, mouseYpos)
);
}
canvas.addEventListener('click', function(e) {
clicked(e);
}, false);
draw();
<!DOCTYPE html>
<html>
<head>
<style>
* {margin:0;padding:0;overflow:hidden;}
</style>
</head>
<body>
<canvas id="canvas">{{-- The background --}}</canvas>
</body>
</html>
I will dare to go outside the scope of our problem because you could prevent such issues in the future by utilizing Array.prototype.forEach, and move the drawing of the dots and constrain them to new functions. With the added benefit of simplifying your code.
// Draw particles
function draw_particles() {
particles.forEach(function(p,pi){
particles.forEach(function(p2,p2i){
if(pi === p2i){
return;
}
// Check X first, maybe we don't need to
// calculate Y
var x = p2.x - p.x;
if ((x *= x) < dist_sq) {
// Check passed, calculate Y
var y = p2.y - p.y;
if (x + (y * y) < dist_sq) {
// Check passed, draw line
draw_line(p.x, p.y, p2.x, p2.y);
draw_dot(p);
constrain(p);
}
}
});
});
}
// Draw particle
function draw_dot(p){
// Color
ctx.fillStyle = color;
// Circle path
ctx.beginPath();
ctx.arc(p.x, p.y, p.radius, Math.PI * 2, false);
ctx.fill();
ctx.closePath();
// Lets use the velocity now
p.x += p.vx;
p.y += p.vy;
// If there is only 1 particle
// show X, Y, and velocity
if (particles.length === 1) {
ctx.fillText('Y:' + p.y, 20, 20);
ctx.fillText('X:' + p.x, 20, 40);
ctx.fillText('YV:' + p.vy, 20, 60);
ctx.fillText('XV:' + p.vx, 20, 80);
}
}
// Constrain particle movement
function constrain(p){
// To prevent the balls from moving out of the canvas
if (p.x < size) p.vx *= (p.vx / -p.vx);
if (p.y < size) p.vy *= (p.vy / -p.vy);
if (p.x > canvas.width - size) p.vx *= (-p.vx / p.vx);
if (p.y > canvas.height - size) p.vy *= (-p.vy / p.vy);
}
Using Array.prototype.length and Array.prototype.forEach reduces the risk of heading into issues of array indices.

how can i make two objects belonging to the same array move independently of each other using javascript and the canvas tag?

I am trying to create a blackhole simulation, where all the balls that are outside of it go away from it at a given speed and those that fall on it are dragged towards the circle until they reach the center of it, where they would stop and disappear, here is my code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>blackhole simulation escape velocity</title>
<script>
var canvas, ctx;
var blackhole;
var circle;
var circles = new Array();
var G = 6.67e-11, //gravitational constant
pixel_G = G / 1e-11,
c = 3e8, //speed of light (m/s)
M = 12e31, // masseof the blackhole in kg (60 solar masses)
pixel_M = M / 1e32
Rs = (2 * G * M) / 9e16, //Schwarzchild radius
pixel_Rs = Rs / 1e3, // scaled radius
ccolor = 128;
function update() {
var pos, i, distance, somethingMoved = false;
for (i = 0; i < circles.length; i++) {
pos = circles[i].position;
distance = Math.sqrt(((pos.x - 700) * (pos.x - 700)) + ((pos.y - 400) * (pos.y - 400)));
if (distance > pixel_Rs-5 ) {
var delta = new Vector2D(0, 0);
var forceDirection = Math.atan2(pos.y - 400, pos.x - 700);
var evelocity = Math.sqrt((2 * pixel_G * pixel_M) / (distance * 1e-2));
delta.x += Math.cos(forceDirection) * evelocity;
delta.y += Math.sin(forceDirection) * evelocity;
pos.x += delta.x;
pos.y += delta.y;
somethingMoved = true;
} else {
var delta2 = new Vector2D (0,0);
var forceDirection2 = Math.atan2(pos.y - 400, pos.x - 700);
var g = (pixel_G*pixel_M)/(distance*distance*1e2);
delta2.x += Math.cos(forceDirection2)*g;
delta2.y += Math.sin(forceDirection2)*g;
pos.x -= delta2.x;
pos.y -= delta2.y;
somethingMoved = true;
circles[i].color -= 1;
if (pos.x == 700 && pos.y == 400){
somethingMoved = false;
};
}
}
if (somethingMoved) {
drawEverything();
requestAnimationFrame(update);
};
}
function drawEverything() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
blackhole.draw(ctx);
for (var i = 0; i < circles.length; i++) {
circles[i].draw(ctx);
}
}
function init(event) {
canvas = document.getElementById("space");
ctx = canvas.getContext('2d');
blackhole = new Ball(pixel_Rs, { x: 700,
y: 400 }, 0);
for (var i = 0; i < 200; i++) {
var vec2D = new Vector2D(Math.floor(Math.random() * 1400), Math.floor(Math.random() * 800));
circle = new Ball(5, vec2D, ccolor);
circles.push(circle);
}
drawEverything();
requestAnimationFrame(update);
}
function Ball(radius, position, color) {
this.radius = radius;
this.position = position;
this.color = color;
}
Ball.prototype.draw = function(ctx) {
var c=parseInt(this.color);
ctx.fillStyle = 'rgba(' + c + ',' + c + ',' + c + ',1)';
ctx.beginPath();
ctx.arc(this.position.x, this.position.y, this.radius, 0, 2 * Math.PI);
ctx.closePath();
ctx.fill();
};
function Vector2D(x, y) {
this.x = x;
this.y = y;
}
function onClick (){
canvas = document.getElementById ('space');
ctx = canvas.getContext ('2d')
canvas.addEventListener ("mousedown", init, false)
blackhole = new Ball (5, {x: 700,
y: 400 }, 0);
blackhole.draw (ctx) ;
}
window.onload = onClick;
</script>
<style>
body {
background-color:#021c36 ;
margin: 0px;
}
</style>
</head>
<body>
<canvas id = "space", width = "1400", height = "800">
</canvas>
</body>
</html>
Now as you can see, I created a second variable called delta2, but the problem is that it can't update the position of the circles, which in term makes it impossible to move the circle, can someone tell me what is wrong. Also, how can I make the big black circle after a certain amount of time, i know i probably should create a timer, but i don't know how they work

The gravity is too weak. I put a pseudo gravity to demonstrate.
var canvas, ctx;
var blackhole;
var circle;
var circles = new Array();
var bh = {
w:500,
h:300
};
bh.cx = Math.floor(bh.w/2);
bh.cy = Math.floor(bh.h/2)
var G = 6.67e-11, //gravitational constant
pixel_G = G / 1e-11,
c = 3e8, //speed of light (m/s)
M = 12e31, // masseof the blackhole in kg (60 solar masses)
pixel_M = M / 1e32
Rs = (2 * G * M) / 9e16, //Schwarzchild radius
pixel_Rs = Rs / 1e3, // scaled radius
ccolor = 128;
function update() {
var pos, i, distance, somethingMoved = false;
for (i = 0; i < circles.length; i++) {
pos = circles[i].position;
distance = Math.sqrt(((pos.x - bh.cx) * (pos.x - bh.cx)) + ((pos.y - bh.cy) * (pos.y - bh.cy)));
if (distance > pixel_Rs - 5) {
var delta = new Vector2D(0, 0);
var forceDirection = Math.atan2(pos.y - bh.cy, pos.x - bh.cx);
var evelocity = Math.sqrt((2 * pixel_G * pixel_M) / (distance * 1e-2));
delta.x += Math.cos(forceDirection) * evelocity;
delta.y += Math.sin(forceDirection) * evelocity;
pos.x += delta.x;
pos.y += delta.y;
somethingMoved = true;
} else {
var delta2 = new Vector2D(0, 0);
var forceDirection2 = Math.atan2(pos.y - bh.cy, pos.x - bh.cx);
// FIX THIS!!!
var g = 1;//(pixel_G * pixel_M) / (distance * distance * 1e2);
delta2.x += Math.cos(forceDirection2) * g;
delta2.y += Math.sin(forceDirection2) * g;
pos.x -= delta2.x;
pos.y -= delta2.y;
somethingMoved = true;
circles[i].color -= 1;
if (pos.x == bh.cx && pos.y == bh.cy) {
somethingMoved = false;
};
}
}
if (somethingMoved) {
drawEverything();
requestAnimationFrame(update);
};
}
function drawEverything() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
blackhole.draw(ctx);
for (var i = 0; i < circles.length; i++) {
circles[i].draw(ctx);
}
}
function init(event) {
canvas = document.getElementById("space");
canvas.width = bh.w;
canvas.height = bh.h;
ctx = canvas.getContext('2d');
blackhole = new Ball(5, { //pixel_Rs, {
x: bh.cx,
y: bh.cy
}, 0);
for (var i = 0; i < 200; i++) {
var vec2D = new Vector2D(Math.floor(Math.random() * bh.w), Math.floor(Math.random() * bh.h));
circle = new Ball(5, vec2D, ccolor);
circles.push(circle);
}
drawEverything();
requestAnimationFrame(update);
}
function Ball(radius, position, color) {
this.radius = radius;
this.position = position;
this.color = color;
}
Ball.prototype.draw = function(ctx) {
var c = parseInt(this.color);
ctx.fillStyle = 'rgba(' + c + ',' + c + ',' + c + ',1)';
ctx.beginPath();
ctx.arc(this.position.x, this.position.y, this.radius, 0, 2 * Math.PI);
ctx.closePath();
ctx.fill();
};
function Vector2D(x, y) {
this.x = x;
this.y = y;
}
function onClick() {
canvas = document.getElementById('space');
ctx = canvas.getContext('2d')
canvas.addEventListener("mousedown", init, false)
blackhole = new Ball(5, {
x: bh.cx,
y: bh.cy
}, 0);
blackhole.draw(ctx);
}
window.onload = onClick;
body {
background-color: #021c36;
margin: 0px;
}
<canvas id="space" , width="700" , height="400"></canvas>